muzik wrote: So what about a reaction that moves at c/9 diagonal or so?

I kinda miss the point looking for reactions, which are pretty rare and even when found are not capable of supporting anything else except that specific speed, using some constructible monster.

I think this is kinda nice when the reaction exists - but meanwhile there are design patterns and everything ready for universal spaceships speeds (even for oblique case and diagonal case), which are kinda on hold (admittedly it's a lot of work).

Why would anyone invest a lot of effort to build specific speed with specific reaction, instead of building universal speed, based on simple stuff like gliders, *WSS, slow salvos and conduits?

muzik wrote:Think about it. The [s]witch engine alone isn't actually a puffer, it d[I]es out. I'm thinking the same thing for other speeds; a pattern that just produces a copy of itself and can be used to make a ship.

I'm convinced that they're out there somewhere, at some size.

If you're interested in them, please go ahead and figure out how to look for them... I'd love to have some new material like that to play around with.

Unfortunately, just theorizing about reactions' existence is about as productive as just waving my hands wildly and saying, "I think, therefore probably it exists! Someone go look in Plato's Cave for me!" Writing the new better more efficient search algorithms is very much the hard part.

Alternatively, sitting around and waiting for Catagolue to find this kind of thing at random is the slow boring part. A possible way around that is to go out and recruit a few thousand Hacker News readers to run Catagolue searches.

Really that still seems like the angle that's most likely to be productive at the moment...! But it may take more marketing genius than I actually possess.

muzik wrote:The witch engine alone isn't actually a puffer, it does out. I'm thinking the same thing for other speeds; a pattern that just produces a copy of itself and can be used to make a ship.

You actually can use WinLifeSearch to find such patterns, considering people used it for more than 20 years in very different configurations I highly doubt we missed something so profound.

You can also write your own search utility - but for that you will need some more specific idea, how what you're imagining, can be found faster with what you're suggesting.

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I initially thought you were talking about something more modest like the pi climber, there are about 6-8 such interactions known and they're pretty rare but possible, some of them were the building blocks for constructible spaceships (caterpillar, waterbear, HBK, centipede). What you're talking about is even rarer, and much much harder to find.

I still don't see the point of imagining and hoping for some miracle, instead of investing effort to build something which is known to be possible to build and will certainly work.

simsim314 wrote:I still don't see the point of imagining and hoping for some miracle, instead of investing effort to build something which is known to be possible to build and will certainly work.

I lean toward that point of view also -- but I think I understand muzik's point of view pretty well also. No matter how impressive an engineered universal spaceship gets built, it won't change the annoying fact that there are gaps in the Elementary Spaceships table.

It wouldn't be so bad if we could be sure that no spaceships exist at those speeds... but I think we can guess fairly confidently that c/8 and c/9 elementary spaceships _do_ exist, at some size. But the search haystack is so large that we can't find the needle...

It's interesting that what our search tools are good at finding is long thin / short wide / diagonally narrow spaceships, but for most periods those probably aren't the smallest population ships that are out there. If we could inspect all the record-breaking smallest period-N ships stored in Plato's Cave, from N=2 to N=very large, it seems to me they'd probably mostly be fairly thin fairly short asymmetical blobs -- getting bigger on average as the period goes up, but not getting up as far as Spaghetti Monster length for quite a while.

Has anybody tried a lifesrc-like search that's not exhaustive, but instead makes arbitrary decisions every now and then and skips large parts of the search space? Maybe a workable way to find a blob-shaped higher-period spaceship would be to set a randomized lifesrc running for a few months. Every time it gets to the end of a search cycle in less than an hour, it should cut its probability of making an arbitrary choice by say 10% -- and every time a search cycle takes more than an hour it should increase that probability by 10%.

That would at least search different corners of the search space on every cycle. If there are a lot of spaceships out there in the search space, it might be more likely to happen on one, than an exhaustive lifesrc algorithm that keeps getting stuck trying every possibility in some useless corner of the space.

-- Probably not, though. The great advantage of exhaustive searches is that if you can get all the way through one, you've actually learned something. Running a randomized searcher would probably get discouraging fairly quickly.

I don't see the real distinction between the "natural" and "constructed" - and I totally don't see the point in quest for "elementary" ships (I do see the point in looking for smaller ships though). Think of glider guns, how many "true" or "elementary" guns there are? Can you say that Gosper gun is constructible or "elementary"? Most of the guns are heavily constructible, while others have fewer artificial artifacts and based on cool reaction, but I don't see anyone "criticizing" guns for their property of being constructed and not "elementary", there are just too much constructed guns and they do the job. Obviously you would prefer smaller guns, and guns based on oscillators and reaction tend to be much smaller.

All in all somehow in case of guns we got used to the fact that you can't expect them all to work "by magic", and some basic components are combined together to build guns. In the case of ships, we need this "magic" to happen - because it did happened for low periods...but if you think of it, large periods "magic" in guns is way more common than large period magic ships (in ships we have only SE, and maybe copperhead, while in guns we have all kinds of period and oscillators/reactions p20, p22, p30, p36, p46, p120 etc.).

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As for randomized searches - they could be good for A* search (I think this is the term) i.e. to prioritize the order of the exhaustive search.

dvgrn wrote:But reactions that run at c/9 and don't need continuous outside support are either spaceships in their own right, or they're puffers of some kind. Puffers analogous to the switch engine do show up in all sorts of rules, but if they happened very often in B3/S23, Catagolue would have catagolued a bunch of them by now.

I'm still surprised that that hasn't happened, actually. A self-sustaining repeating reaction seems like it shouldn't be so unlikely -- bounce a pi-heptomino off a beehive, let's say, and happen to produce some junk and another pi-heptomino... and another beehive offset by the same amount.

It's that last "offset by the same amount" that brings the odds down so close to zero, along with the unspoken caveat "and no other random junk that happens to get in the way."

I sometimes wonder if there's something analogous to the switch engine out there, maybe a bit rarer, that doesn't have a one-engine stabilization, so wouldn't have been found by Catagolue, but could still have stabilizations with multiple engines. I suppose it could theoretically travel at c/9.

dvgrn wrote:But reactions that run at c/9 and don't need continuous outside support are either spaceships in their own right, or they're puffers of some kind. Puffers analogous to the switch engine do show up in all sorts of rules, but if they happened very often in B3/S23, Catagolue would have catagolued a bunch of them by now.

I'm still surprised that that hasn't happened, actually. A self-sustaining repeating reaction seems like it shouldn't be so unlikely -- bounce a pi-heptomino off a beehive, let's say, and happen to produce some junk and another pi-heptomino... and another beehive offset by the same amount.

It's that last "offset by the same amount" that brings the odds down so close to zero, along with the unspoken caveat "and no other random junk that happens to get in the way."

I sometimes wonder if there's something analogous to the switch engine out there, maybe a bit rarer, that doesn't have a one-engine stabilization, so wouldn't have been found by Catagolue, but could still have stabilizations with multiple engines. I suppose it could theoretically travel at c/9.

I think the closest search program for that seems to be gsearch. It can seperate objects if they are farthwr apart than the param you specified

I completed an unsuccessful search for c/8, width 15, bilaterally symmetric with gfind-pt some time ago and haven't seen anyone else mention a result for it, So here are the longest partials resulting from that search:

So searching for ships in b3s23 is more of a challenge than a chore then? I see.

Back on the topic of potential c/9 reactions and such: If someone could be as kind as to search for a c/12 diagonal ship using a search program of some sort. If a switch engine of some sort pops up, then this kind of confirms that non-spaceship c/9 reactions might be easy to find?

muzik wrote:Why do the gap-filling speeds of c/8 and c/9 have to be so elusive...

Look at the spaceship search status page for ships of periods 5, 6, and 7. With the exception of a small 2c/5 gutter ship, every single speed at these periods requires a search-width of at least 9. We have only searched (1,0)c/8 up to a search-width of 8. If we had found a ship at that width, it would be abnormally thin. In that sense, I don't think the (1,0)c/8 ship is particularly elusive.

muzik wrote:Anyway, on the Cordership shrinking project?

This is likely to be a very difficult task (unless someone gets extremely lucky). I also don't think it's very high on anyone's priority list. If you want this project to get done, you will probably have to do it yourself.

muzik wrote:If someone could be as kind as to search for a c/12 diagonal ship using a search program of some sort. If a switch engine of some sort pops up, then this kind of confirms that non-spaceship c/9 reactions might be easy to find?

The only search programs that could currently find a switch engine are programs that run random patterns. Direct spaceship search programs could, at best, find a period-12 ship. The switch engine has period 96! Also, If you want these searches done, you will probably have to do them yourself. WLS seems to be the best program for diagonal searches.

With all due respect, I really think you should familiarize yourself with the different kinds of search programs and their limitations before you continue to request that other people do things for you. Especially difficult/outstandingly nontrivial tasks like the kind you're asking for.

The easiest program to understand might be JavaLifeSearch due to it's nice user interface. It's a nice program to play around with. You don't have to discover anything new at first. Just using it to find known patterns can help you understand its limitations. The biggest limitations are usually the size of the search area and the period of the search.

WLS and JLS are essentially the same. I suggested JLS instead of WLS, because JLS is not platform dependent. Anyway, understanding the limitations of WLS can help you understand the limitations of other spaceship search programs. Especially, notice how much longer searches take as you increase the period. Period-9 is almost too much for WLS to handle. Finding something like the switch engine, at period-96, is far out of the reach of WLS.

That's because period-8 is very high for WLS. If you want to practice using WLS, you might try finding known patterns that are lower-period. There are also a lot of low-period searches that simply haven't been done, so there's still room for discovery there. Extending partial results and using strangely-shaped search areas can possibly give interesting new results at low periods.

You can also try searching for spaceships in other rules. That way, you can find new patterns while also learning how to use WLS better.

The 7c/40 is a pretty well-known one. I've brought up the concept of a replicator based on it multiple times in this thread, but focusing on a spaceship first might make finding the replicator a bit easier.

There are a lot of known waves, but so far no one has been able to get one to stabilize itself (the closest thing is this puddle jumper relative in DryLife, but that's mostly just due to luck). As has already been mentioned, the periods of these waves are way too high to search for a stabilization directly. If you want to see spaceships made from these, or any other waves, you will probably need to find a radically new spaceship design.

Also, people have been trying to make a 9c/30 pi ship for at least the last 20 years, with very little progress made in that time.